1. Field of the Invention
The invention is primarily directed to a technique for printing carpet, and more particularly, to a printing technique that uses sublimable dyes on a transfer sheet that is placed adjacent the back of the carpet for printing a pattern on the carpet face yarns.
2. Description of the Prior Art
U.S. Pat. No. 3,782,896 discloses it is old to use transfer printing operations to print carpet designs.
Transfer printing through the use of sublimable dyes is an old art. Normally, the dye is carried on a transfer carrier or sheet and the transfer carrier is placed up against the surface to be dyed. Through the use of heat and pressure, the sublimable dyes are converted to a vapor stage and transferred to the material adjacent the transfer carrier. The transfer carrier is then usually discarded. Normally, the transfer carrier is non-porous. Also, the prior art suggests the use of vacuum to achieve greater depth of printing.
U.S. Pat. No. 3,707,346 teaches the above concept of transfer printing and suggests the use of a heated roll, a heated plate, or steam or dry, warm air under atmospheric pressure or in a vacuum to cause transfer printing.
The inventive technique herein is the utilization of a porous transfer carrier or sheet for the printing of the face yarns of a carpet. Herein, specifically, the transfer is carried out through the use of a heated gas which is controlled as to its temperature and flow so as to provide controlled displacement of the sublimable dyes from the porous transfer sheet to the face carpet yarns of the finished carpet product. The transfer sheet is not positioned adjacent the face carpet yarns of the carpet product, but is placed against the back of the carpet product.